/**
 * 字符串转码  多字节字符转多单字节
 * 		eg:'a啊b'=>'a\xE5\x95\x8Ab'
 * @param v string 字符串
 * @return string
 */
$.char = function(v){
	let B;  v=encodeURIComponent(v+'');
	B=(a,m)=>String.fromCharCode(parseInt(m,16));
	return v.replace(/%([a-f0-9]{2})/ig, B);
};
